Grinding ok polishing machine



E. CAVICCHI.

GRINDING 0R POLISHING MACHINE.

APPLICATION FILED JULYI5,19IB.

Patented Aug. 5, 1919 Fig.1.

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EBGOLE'GAVICCHI, OF QUINCY, MASSACHUSETTS.

GRINDING OR POLISHING-MACHINE.

Specification of Letters Patent.

Patented Aug. ,5, 1919.

Original application filed November 22 1915, Serial No. 62,755. Divided and this application filed July 15,

- 1918. Serial No. 244,866.

To all whom it may concern:

Be it known that I, ERooLE CAVI CHI, a citizen of the United States, and resident of Quincy, county of-Norfolk, State of Massachusetts, have invented an Improvement in Grinding or Polishing Machines, of which the following description,in connection With the accompanying drawing, is a specification,

like characters on the drawing representing like parts.'

This invention relates to improvements in grinding or polishing machines of the type in which a rotary grinding or polishing member is pushed backward and forward over the surface to be polished such as marble, mosaic, terra'za or other composition flooring and comprises certain improve ments disclosed in my prior Patent No. 1,126,615, granted October 26, 1915, and is a division of my pending application Serial No. 62,755, filed November 22, 1915. i

The present invention like that disclosed in my prior patent aforesaid comprises a rotary grinding head having a plurality of abrasive members adapted to rest upon the surface to be ground, said head being actuated by a motor preferably an electric motor.

The motor rests upon a platform which is supported at one end by the rotary grinding head and at the other end by a pair of wheels. In my prior patent aforesaid "means are provided for supporting a weightdirectly over, the grinding head in order to press the same firmly against the surface being ground, thereby increasing the effi-' ciency of the tool. v

One of the objects of the present invention is to so construct the machine that a greater portion of the weight of the motor is carried by the grinding head thereby greatly increasing the normal pressure of thegrinding means upon the surface being treated.

In the use of grinding machines of this character it is desirable that the machine;

should be so constructed that it maybe operatedas far into the corners of theroom as possible and also that it may be turned around in a relatively small space. Y

. Another object of the invention therefore is to construct the machine so that it will be tained uniform notwithstanding the uneven- I ness of the surface being treated.

Another object of the invention is to provide a novel form of driving mechanism which will enable the vertical shaft which actuates the grinding tool to be carried beneath the motor. 7 j Anotherfeature of the invention consists in so constructing the casing for the gearing through which the motor drives the grind-' ing tool that it may be quickly and readily dlsmantled for the purpose of cleaning or replacement.

A furtherfeature of the invention comfor said gearing.

.Other objects and features of the invention will more fully appear from the followlng description and accompanying draw- 1 lugs and will be pointed out in the annexed claims.

In the drawings; 1 Figure 1 1s a vertical longitudinal section of the grindin and polishing machine embodying a pre erred form of my invention the motor and certain shafts being shown in elevation.

Fig. 2 is a plan view of the machine, the motor having been removed.

The grinding and polishing machine illustrated herein comprises a platform 1 in the form of a casting having stands 2 adapted to support an electric motor 3. The casting forming the platform preferably is so constructed as to provide a casing for the gears which actuate the grinding tool and sists in providing a novel dust proof casing also, provide journals for the necessary' shafts. As illustrated in Fig. 1 the central portion of the platform casting has "a down- .wardly ofi'set portion 4 which provides a casing for a gear 5 which actuates the shaft 6 which drives 'the rotary grinding head 7.

' This downwardly'ofi'set portion of the casing also comprises a boss 8 which forms a journal forthe shaft 6. The forward portion of this offset extension merges into a semi-annular casing 9 which incloses a gear 10 rotatable about a stud shaft ,11 which is journaled at its outer end in a thickened boss 12 at the uppercent'ral portion of said casing 9. The members of the platform 1,the downwardly ofl'set casing 4, the boss 8, the casing 9 and the boss 12 preferably are integral, thus forming a very-rigid structure, The opposite end of the shaft 11 is secured in a socket 13 in the central portion 14' of a cover 15 for the-casing 4 which is of generally circular form but provided with extensions or ears 17. and 18 loy which it is secured to the platform by suitable bolts 19. The central portion 14 of the cover is provided with a downwardlyextending boss which forms a socket or bearing for the upper end of the shaft 6, suitable antifriction means such as disks 16 being provided to form a thrust bearing.-

The shaft 11 is secured in the so ket 13 by a set screw 20 or in any, other suitable manner and has rotatably mounted upon it a beveled gear 21- which engagesthe gear 5.

'5 The beveled gear 21 has anextended hub 22 upon which the hub 23 of the gear 10 is secured by a key 24. The gear 10 engages a gear 25 ;of smaller diameter. which is secured uponthe shaft 26 of the electric motor 3. It will be obvious that the rotation of the shaft 26 will cause the gear 25. to drive the gear 10 thereby rotating the beveled gear 212-. which in turn .will rotate the gear 5 and with it the rotary grinding head 7.

In order' to provide proper lubrication for the relatively rotating parts the stud shaft 11 preferably isuprovided with a central duct 27 having communicating apertures 28 leading to the surface of said shaft, said apertures being positioned at desirable intervals fwit-hinthe hub of the gear'21.

An oil port 29, leading to the'socket 13 for the end :of the stud shaft 11, provides means for supplying oil to the duct 27. A port 30 also may lead from the thrust bearing at the end of the shaft 6 into the socket .13, whereby oil introduced into the socket 13 will serve to lubricate the bearing of the beveled gear 21 and also the thrust bearing of the shaft 6. The shaft 6 may also be provided with'acentral vertical oil duct 31 having a lateral port for lubricating the journal of said shaft whichlies within the downwardly extending boss 8, said duct being supplied by a usual grease cup or reservo1r.. a a

The lower end of the journal within the boss 8 desirably is provided with a gland 32 which will prevent the escape of oil at the lower end of said journal. A semi-cylindrical casmg 33 secured to the casing member 9 is provided to inclose the gears 9 and 25 and a disk-like cover 34 having. a central offset port on 34 to cover the beveled gear 21 serves to complete the closure of the gear easing so that dust will be excluded from f the gears.

y The rotary grinding head 7 may be of the character disclosed in my prior application aforesaid of which this constitutes a division and preferably comprises three grinding tools 35 disposed in triangular relation, each of said grinding tools being connected by a universal joint 36 to the rotary grinding head or plate 7-. The grinding tools 35 desirably are composed of ,three abrasive grinding members located in triangularrelation to one another. Bythis construction an equal amount of pressure will be applied to eachabrasive member, for the triangular relation of the tools with their universal connections to the driving head causes each tool to sustain its one third of the weight imposed upon the grinding heal irrespective of the unevenness of the base upon which the grinding tools rest and each of the. abrasive members of each tool for a like reason supports'its proportionate share of the weight imposed upon the grinding tool of which it forms a part. a It will be noted that the platform is supported so that the weight of the motor will bear upon the grinding tools with a uniform pressure, notwithstanding the unevenness of the surface upon which the machine is operated, by reason of the fact that the platform is supported at its front end upon the rotary grinding tool and at its rear end by wheels 37, 38 disposed in triangular relation to the rotary grinding Wheel.

.The wheels 37, 38 are mounted upon an axle 39 which is carried by a frame comprising arms 40', 41 which are pivotally secured to a shaft 42 mounted in'the casing'4. The

arms 40,41 are connected by a cross piece 43 to maintain the same in parallelism and to provide a rigid frame therefor.

' The axle 39 is adjustably secured to the platform by a pair of locking racks 44 having teeth 45, 46 adapted to engage the axle 39. The racks 44 are connected to a shaft 47 carried by" brackets 48 depending from the under face of the platform 1. One of the racks 44 is provided with an integral offset lever 49 adapted to be depressed ,by

the foot of the operator to disengage the racks, 44 from the axle 39. The racks 44 however are normally maintained in engagement with the axle by a helical spring 50 surrounding the shaft 47 and secured at one end to. one of said racks and at its opposite end engaging the under face of the platform. In order to prevent complete disengagement of the racks 44 from the axle 39 and consequently the dropping of the platform I have found it convenient to provide the racks with integral keepers 51 which will permit the racks to be shifted so that their teeth may engage the axle secured together by bolts 55 to form a rigid structure. A switch located upon the handle within easy reach of the operator may conveniently be provided for the purpose of controlling the motor, the usual conductors leading to said switch from a suitable source of power and from said switch to the motor.

In order to prevent the rotary grinding member from coming in contact withthe walls or other vertical surfaces a guard 56 is provided which is in the form of a metallic ring preferably extending entirely around the grinding head nd supported by brackets 57 from the casting which forms the platform and gear easing as above described.

In the operation of the machine the rotation of the motor shaft 26 drives the rochineabout the wheel base as a fulcrum so as to disengage the end 58 of the shaft 6 from its engagement with the socket in the rotary driving head in order thatwheels of different size or of different character may be substituted, thereby adapting the machine readily to any class of work which it is desired toperform.

The rotary grinding head 7 may be equipped with brushes or with other types of tools to perform scouring, bufiing or other special kinds of Work so that the machine is capable of adaptation for various uses with the mere substitution of one tool for another.

It is to be understood that the embodiment of the invention disclosed herein is'illustrative but not restrictive and that various modifications in construction and arrangement of parts may be made within the meaning and scope of the following claims.

Having thus described my invention what I claim as new and desire to secure by Lettary grinding head in the manner above deters Patent is:

scribed. The greater part of the Weight of 1. Ina machine of the class described the motor rests upon the grinding head and comprising a rotary grinding. head having causes the abrasive members to enga e the abrasive means connected thereto, a truck surface being groundor polished more rmly having two Wheels, a platform carried by than is usual in machines heretofore consaid wheels and said rotary grinding head,

structed. This engagement during the rotaa motor located upon said platform, said 'tion of the rotary driving head causes the wheels and grinding head. being arranged machine to move forward and by reason to form a triangular support for said motor, of the fact that the opposite end of the the Tflotor being carriedmainly by said platform which carries the motor issuprotary grinding head, said grinding head ported upon wheels the tool is readily moved having a vertical shaft j ournaled in bearover the surface being treated. As a matings in said platform beneathsaid motor, a ter of fact the rotation of the grinding memgear on said vertical shaft and a system of ber will ordinarily cause the machine togearing positioned to transmit power from progress at about the right speed and it is the shaft of the motor to the gear upon the only necessary to guide the same by the :vertical shaft. handle. By virtue of the shortbaselength 2. In a machine of the class described between the rotary grinding tool and the comprising a rotary grinding. head having wheels which support the opposite end of abrasive means connected thereto, a truck the platform a compact construction is prohaving two wheels, a platform carried by vided which will permit the grinding tool said wheels and said rotary grinding head, to work well into the corners of the room. a motor located upon said platform, said The lower end of the shaft 6 is provided wheels and grinding head being arranged with an angular enlarged section 58 having to form a triangular support for said motor, 'a central hemispherical extension 59, The the motor being carried mainlv by said 'rorotary grinding head- 7 is provided centary grinding head, said grinding head havtrally with a socket having an angular poring a vertical shaft, provided with an angu- 'tlOl'l 60 to receive the angular portion 58 lar head engaging a complementary socket of the shaft and also with a hemispherical in said grinding head, journaled in bearings socket 61 to receive the extension 59 of said shaft. shaft of the motor with said vertical shaft.

In the operation of the machinev the hemi- 3. In a machine of the class described spherlcal extension serves to maintain the comprising a rotary grinding head having a proper centering of the shaft in the rotary vertical shaft and provided with abrasive grinding head while the angular portion members, a platform, a motor supported by causes proper-engagement between the shaft said platform over said grinding head, said and driving head to cause rotation of the platform comprising. offset portions Providlatter. ing a gear casing and a journal for the shaft By reason of the short base of the maof said rotary grinding head, a cover for chine the operator can, by pressing upon said gear casing having a thrust bearing for the handle, ralse the front end of the mathe shaft of said rotary grinding head, a. stud in said platform and gearing connecting the shaft having one end mounted in said cover and supported at its opposite end by said gear casing, and gears upon said stud shaft engaging respectively the gears upon the shaft of the motor and upon the shaft of the rotary grinding head.

4. In a machine of the class described comprising a motor, a rotary grinding'head having abrasive means connected thereto, a train of gears operating to drive said grinding head from said motor, a platform supporting the said motor having offset portions forming a casing for said train of gears, a cover for said gear casing-having means for receiving the adjacent ends of the shafts of said gears, the opposite ends of said shafts being mounted in said gear casing. I

5. 'In a machine of the class described comprising a platform, a motor on said platform, a truck supporting the rear end of said platform, a rotary grinding head having abrasive means connected thereto and having a vertical shaft journaled in said platform, beneath said motor supporting the front end of said platform, a horizontal stud shaft removably secured in said platform,

gears on said motor shaft and the vertical shaft of said grinding head, and reducing 7 gears mounted upon said stud shaft engaging respectively the gears upon said motor shaft and the gears upon said vertical shaft.

,6. In a machine of the class described comprising a platform, a motor on said plat form, a truck supporting the rear end of said platform, a rotary grinding head having abrasive means connected thereto and reducing gears, and means for lubricant to said duct.

comprising a platform, a motor on said platform, a truck supporting the rear end of saidiplatform, a rotary grindingihead hav ingabrasiv'e means connected thereto .and having a vertical shaft journaled in said. platform beneath said motor supportin the frontend of said platform, a horizonta stud shaft removably secured in said platform, gears on said motor shaft and the ver-, tical shaft of said' grinding head, reducing gears mounted upon said stud shaft engagmg respectively the gears upon said motor shaft and idle gears upon said vertical shaft,

an axial duotin said stud shaft having 65 ports leading to its surface within said reducing gears, means forsupply ing lubricant to said duct, and a duct leading from said lubricant supplying means to the journal" of said vertical shaft. I

In testimony whereof I have signed my name to this specification.

- ERCOLE CAVIOOHI',

supplying v 7. In a machine of theflclass described 

